Medical imaging technologies such as CT, MRI and Ultrasound are widely used in the detection of abnormal tissue such as tumors. There are various types of abnormal tissue. For example, tumors in the same organ can be benign or malignant.
Ultrasound is especially suitable for immediate assessment pre or post tumor resection before closing the chest in the surgery. In the case of a liver tumor, for example, before and/or after resecting the tumor identified, the surgeon may use intraoperative ultrasound (IOUS) to search the whole liver to identify any undetected suspicious small tumor (for example: diameter less than 5 mm) which has been previously missed by conventional trans-abdominal ultrasound examination, or a residual tumor. In comparison with trans-abdominal ultrasound, IOUS has several advantages, including: IOUS does not suffer from the acoustic attenuation caused by the abdominal wall and thus may utilize a higher frequency to obtain a higher spatial resolution; the liver has to be “spied” on within the acoustic windows (e.g. trans-costal) in the trans-abdominal ultrasound, whilst the IOUS probe can be placed in contact with the anterior, superior, inferior or posterior liver surface and the tissue of interest can be studied from different points of view; during IOUS, information obtained by means of the ultrasound and information obtained by inspection and palpation can complement each other.
However, IOUS has the same drawback as trans-abdominal ultrasound, namely that visual observations of ultrasound images are highly dependent on an operator's experience. Surgeons are often not equipped with the same level of ultrasound skills as their surgical skills. In practice, ultrasound doctors with sophisticated ultrasound skills are often asked by surgeons to come to the operating room to evaluate the ultrasound images. Even for ultrasound doctors, the evaluation of ultrasound images is not easy due to the limited time available for IOUS. Therefore, highly specialized training is required for this task. Even so, the evaluation results are operator-dependent.
U.S. 2014/0288424 A1 discloses a method and a device to image and characterize human tumors, ad to classify the tumors as either malignant or benign. The method includes using a multi-compression technique upon the tissue or organ combined with a 3 ultrasound strain imaging of the compressed tissue or organ for acquiring raw data and analyzing the raw data using a computer processing unit equipped with a nonlinear biomechanical tissue model for tumor classification.